The present invention relates to a machine for the wrapping of articles in stretchable film of soft plastic material.
There are known, for example from U.S. Pat. No. 3,662,513 (FABBRI) and from U.S. Pat. No. 3,967,433 (BONFIGLIOLI), machines which carry out the wrapping of articles in stretchable foils of soft plastic material. Such machines of the prior art present however the inconvenience, whenever it is desired to wrap in a single package a plurality of loose articles, such as for example bottles or cans, that the said articles must be placed in suitable tray-like receptacles, since, during the wrapping operation, the whole item to be packaged is deposited on a vertically reciprocating lifting table the supporting surface of which is equipped with upwardly projecting supporting fingers or webs which are intended to be resiliently tipped over under the action of the folders which fold the edges of the film under the item. Obviously, the presence of the said upwardly directed resilient fingers or webs does not allow the stable positioning on the moving table of articles having a relatively small base such as bottles or cans. The problem of the stable positioning of this type of articles becomes precisely more evident in the case that it is desired to wrap in a single package a plurality of articles loosely arranged the one adjacent to the other.
It is the main object of the present invention to provide a machine for wrapping articles in stretchable film, which can wrap in a single package a plurality of articles such as bottles, cans, small boxes or the like, loosely arranged in groups of predetermined number.
It is a further object of the present invention to provide a machine for the wrapping of any articles in stretchable film, presenting remarkable operational speed characteristics, even higher than the operational speeds of the known machines.
In the machine according to the invention, the item to be packaged is supported by a platform which presents a horizontal flat surface onto which the item to be wrapped (consisting of one or more articles) can be steadily positioned without the need of a support container or tray, and onto which surface the item can be slidably moved, during the completion of the wrapping operation without prejudice for its stability.
The said platform is moved along a substantially quadrangular path, effecting sequentially a lower horizontal run, during which it is loaded with the article (or articles) to be wrapped, a upwardly directed vertical run, which brings the article in contact with the wrapping film and during which the proper wrapping cycle is started, a horizontal upper run, during which the wrapping operation is completed, and in the meantime the article being wrapped is gently transferred away from the platform, and a downwardly directed vertical run, which brings again the platform to its loading position.
The closed-circuit continuous translatory movement of the platform along the mentioned quadrangular path consents therefore high operational speeds, which cannot be attained by the known type machines which employ vertically reciprocating platforms.
The above and other objects and advantages of the wrapping machine according to the invention will appear evident from the following detailed description of a peferred embodiment of same, made, by way of non-limiting example, with reference to the attached drawings.